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  • Committer: Bazaar Package Importer
  • Author(s): Ian Lynagh (wibble)
  • Date: 2003-10-01 12:31:01 UTC
  • Revision ID: james.westby@ubuntu.com-20031001123101-yquo14mvjqh3e0sk
Tags: upstream-2.0
Import upstream version 2.0

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alex/tests/tokens.x
 
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{
 
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module Main (main) where
 
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import System.Exit
 
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}
 
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%wrapper "basic"
 
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$digit = 0-9                    -- digits
 
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$alpha = [a-zA-Z]               -- alphabetic characters
 
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tokens :-
 
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  $white+                               ;
 
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  "--".*                                ;
 
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  let                                   { \s -> Let }
 
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  in                                    { \s -> In }
 
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  $digit+                               { \s -> Int (read s) }
 
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  [\=\+\-\*\/\(\)]                      { \s -> Sym (head s) }
 
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  $alpha [$alpha $digit \_ \']*         { \s -> Var s }
 
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{
 
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-- Each right-hand side has type :: String -> Token
 
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-- The token type:
 
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data Token =
 
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        Let             |
 
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        In              |
 
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        Sym Char        |
 
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        Var String      |
 
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        Int Int         |
 
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        Err 
 
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        deriving (Eq,Show)
 
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main = if test1 /= result1 then exitFailure
 
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                           else exitWith ExitSuccess
 
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test1 = alexScanTokens "  let in 012334\n=+*foo bar__'"
 
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result1 = [Let,In,Int 12334,Sym '=',Sym '+',Sym '*',Var "foo",Var "bar__'"]
 
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}